The proliferation of high data rate communication equipment in diverse user environments such as local area networks and VSAT systems, has increased the demand for electromagnetic impulse protection devices in a variety of system applications. As such, a particular requirement of such devices is that they appear invisible to signalling traffic; namely, they do not degrade the quality of the communication signal, for example, by way of insertion loss and unwanted signal reflections on the transmission line. An example of a conventional electromagnetic impulse device that is intended to be installed in a high frequency communication link without effectively creating a mismatch with the characteristic impedance of the line is described in the U.S. Pat. No. 4,409,637. According to the patented scheme, the increased capacitive reactance imparted by the coupling of a surge-suppressing (gas) discharge device between the center conductor and shield conductor of the transmission line is compensated by increasing the inductive reactance of the device, via control of the dimensions of the shield (ground plane) conductor and inductor segments that are coupled in circuit with the shield conductor structure. Unfortunately, although the patented device functionally serves its intended purpose, its diverse, multicomponent hardware configuration makes it expensive to manufacture.